公开(公告)号：US06409969B1

公开(公告)日：2002-06-25

申请号：US09323199

申请日：1999-06-01

申请人： Steven R. Streicher ,  James A. Freeman ,  John E. Taylor

发明人： Steven R. Streicher ,  James A. Freeman ,  John E. Taylor

IPC分类号： G01N3112

CPC分类号： G01N27/123

摘要： The present invention contemplates a system and method for controlling or adjusting the accuracy of an exhaust gas sensor utilizing the impedance of the sensing element. In one embodiment, a periodic AC signal is superimposed over low frequency or DC output signal produced by the gas sensor. The AC current flowing through the gas sensor is a function of the actual impedance of the sensor, which is in turn a function of the temperature of the sensor. Thus, the invention further contemplates an impedance sensor circuit connected to an output of the gas sensor. The output of the impedance sensor circuit is a peak voltage that is indicative of the AC voltage drop across the sensor, and ultimately the impedance of the sensing element. This peak voltage is utilized to control the operation of the heating element in a closed loop control system in which the thermal output of the heating element is continuously varied as a function of the magnitude signal to accurately maintain a consistent temperature for the exhaust gas sensor. In a specific embodiment of the invention, the impedance sensor circuitry includes a bandpass filter centered around the frequency of the superimposed AC signal to eliminate spurious noise. The output from the bandpass filter is provided to a half-wave rectifier, the output of which is the peak voltage signal indicative of the sensor impedance.

摘要翻译： 本发明考虑了利用感测元件的阻抗来控制或调节排气传感器精度的系统和方法。 在一个实施例中，周期性交流信号叠加在由气体传感器产生的低频或直流输出信号上。 流过气体传感器的交流电流是传感器的实际阻抗的函数，传感器的阻抗又是传感器温度的函数。 因此，本发明进一步考虑了连接到气体传感器的输出的阻抗传感器电路。 阻抗传感器电路的输出是表示传感器上的AC电压降的峰值电压，最终表示感测元件的阻抗。 该峰值电压用于控制闭环控制系统中的加热元件的操作，其中加热元件的热​​输出作为幅度信号的函数连续变化，以准确地维持排气传感器的一致的温度。 在本发明的具体实施例中，阻抗传感器电路包括以叠加的AC信号的频率为中心的带通滤波器，以消除杂散噪声。 来自带通滤波器的输出被提供给半波整流器，其输出是表示传感器阻抗的峰值电压信号。

公开(公告)号：US07234864B2

公开(公告)日：2007-06-26

申请号：US10955765

申请日：2004-09-30

申请人： Steven R. Streicher

发明人： Steven R. Streicher

IPC分类号： G01K7/00

CPC分类号： G01K7/13 ,  G01K1/026

摘要： The cold junction temperature of the channels on a multi-channel terminal block are accurately determined for each terminal pair without affixing a thermistor to each terminal. One embodiment provides accurate cold junction measurement of a six channel device (12 terminals) by mounting or directly affixing only three sensors (e.g., thermistors). The present technique decreases cost by reducing the number of sensors to less than the number of channels or terminals, while providing for accurate cold junction measurement at each channel.

摘要翻译： 对于每个端子对，准确地确定多通道端子块上的通道的冷结温度，而不将热敏电阻贴在每个端子上。 一个实施例通过安装或直接固定三个传感器（例如，热敏电阻）来提供六通道装置（12个端子）的精确冷端测量。 本技术通过将传感器的数量减少到小于通道或端子的数量来降低成本，同时在每个通道提供准确的冷端测量。